This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 987654103 |
| 2 | 987654301 |
| 3 | 9876541023 |
| 4 | 9876542103 |
| 5 | 9876543102 |
| 6 | 9876543201 |
| 7 | 9876543210 |
| 8 | 9876542130 |
| 9 | 9876543120 |
| 10 | 9876534120 |
| 11 | 9876345120 |
| 12 | 9876514032 |
| 13 | 9876431250 |
| 14 | 9876045312 |
| 15 | 9875324160 |
| 16 | 9876523104 |
| 17 | 9863147520 |
| 18 | 9875312640 |
| 19 | 9635217408 |
| 20 | 9845637120 |
| 21 | 9715064832 |
| 22 | 9574023168 |
| 23 | 9805234176 |
| 24 | 5892341760 |
| 25 | 6398410752 |
| 26 | -1 |
| 27 | -1 |
| 28 | -1 |
| 29 | 536870912 |